Engineer&#39;s instrument



April 28, 1931. I O HERM 1,802,603

ENGINEER S INSTRUMENT Filed Sept. 8, 1925 frzwmar I ,4

Patented 28, 1931 PATENT OFFICE OLE G. HERM, F MARSHALLTOWN, IOWA.

ENGINEERS INSTRUMENT Application filed September 8, 1925. Serial No. 55,048;

The object of my invention is to provide an instrument of simple, durable and inexpensive construction, which may be used by engineers, and particularly adapted to be used in connection with setting grade or cross sec tion stakes for excavation or embankment, and to provide meanswhereby the engineer may easily and quickly determine the position of the stake without tedious calculations,

either mental or otherwise.

My invention consists in the construction, arrangement and combination of the various parts of the device, whereby the object contemplated is attained, as hereinafter more fully set forth, pointed out in my claims, and illustrated in the accompanying drawings, in which: i

Figure is a perspective view of my improved'instrument, the graduations of the scales being omitted.

Figure 2 is a plan view of the same showing the manner in which the scales are grad- Figure 3 is a detail sectional view taken on the line 3-3 of. Figure 2.

Figure is a diagrammatical view illustrating the manner iii-which my improved instrument is used in connection with setting stakes.

My improved instrument comprises a body portion 10 which is formed preferably rectangular, having in each of its side edges a groove ll. The top face of the body portion 10 is provided with two longitudinally ex tending grooves 12 and 13. Each of said grooves has its side edges provided with grooves 14. The groove 12 is provided with a slide bar 15, each edge of which is provided with a tongue 16 designed to enter the grooves 14. The groove 13 is provided with a slide bar 17 similar to the slide bar 15.

v The under face of each of the slide bars 15 and 17 is provided with a rack bar 18, each of which is designed to mesh with a pinion 19. Each of the pinions19 is mounted on a shaft 20, the outer end of which is provided with a hand wheel 21. One of the shafts 20 extends laterally from one side edge of the member 10, while the other one extends laterally'from the opposite side edge, as clearly shown in Figures 1 and 2. This provides means whereby the slide bars 15 and 17 may be moved longitudinally in their respective grooves by simply rotating the hand wheels 21.

Mounted above the upper face of the member 1.0 is a rectangular frame 22 having a transparent member 23. Each end of the member 22 is provided with a downwardl extending portion 24, the lower end of each of said portions being bent inwardly to enter the grooves 11. The transparent member 23 is provided with a hair line 25.

The upper surface of the central portion of the body 10, which lies between the grooves 12 and 13, is provided with a graduated scale 26, the graduation lines extending transverse ly therewith. The central portion of the said scale is provided with the character G indicating the grade line. The scale is then divided into an equal number of transverse divisions above and below the said character G, the divisions extending above-the character G are designated by suitable numerals of one color, while the divisions below the character G are designated by another set of numerals, either of a different color or in some way marked to distinguish them from the numerals above the said line; The characters above the point G are designed referably to indicate the number of feet 0 embankment required at a particular station, the upper end of the scale being provided with the character F to indicate embankment. The characters below the point G are designed to indicate the number of feet of excavation required at a given station, the lower end of said scale being provided with the character C. These feet divisions may be provided with any suitable subdivisions, such as tenths, hundreths or thousandths.

The slide bar 15 is provided with two scales 27 and 28 which are graduated, said graduations being arranged in groups of ten. The graduations of each group are provided with the digits, the digits of one scale being designed toread upwardly, while the digits of the opposite scale are designed to read downwardly. The end of the scale 27 is provided with the character E, while the scale 28 is provided with the character R. The scale 27 is designed to be used with an elevation rod, or a rod designed to read elevations direct, the numerals thereon indicating grade elevations, and elevations at the point where the slope stakes are set. The scale 28 is designed to be used with the ordinary leveling rod, the numerals thereon indicating grade rod readings, and rod readings at the points where the slope stakes are set. In Figure 2 the slide bar 15 is properly placed to be used with rod reading elevations direct. If the ordinary leveling rod is used, the slide bar 15 has to be turned end for end in the frame. These graduations are also read in feet and subdivisions thereof.

The slide bar 17 is provided with a scale 29 which is graduated into a number of equal divisions, the alternate divisions being provided with numerals of one color, while the other divisions are provided with numerals of another color, preferably black and red. The red numerals of said scale as illustrated in the drawings are distinguished from the black numerals by placing a small horizontal line 30 beneath them. The black numerals are designed to read upwardly, while the red numerals are designed to read downwardly.

The upper end of the scale 29 is provided with a red characterC and a black character F. The character C indicates that the scale is to be used with sections in excavation and the character F indicates that the scale is to be used with sections in embankment. The black numerals of said scale are also designed to indicate the number of feet from the center of the finished road bed or grade to of the scale 29 are provided for a predetermined side grade or side slope, of the excavation or embankment, the lower end of the said scale being provided with characters to designate the side slope for which the scale is designed to be used, and in the one illustrated in the drawings the side slope is one and one-half to one. It will be seen that a separate slide bar 17 will have to be provided for each slope. Said slide bar can easily be removed longitudinally through the groove 13.

In Figure 4 I have provided a diagram in which the vertical line aa indicates the vertical center line of the finished grade or roadbed, the line G'-b indicates one-half of the finished transverse grade line, the line b-c indicates one side of the finished slope in embankment the line de indicates one side of the finished slope in excaVation,-the line f-h indicates the transverse profile of the natural ground of one station in excavation, and the line j-lc indicates the transverse profile of the natural ground at another station in embankment.

In actual practice, if the section is in excavation, a stake is set at the point 31 where the profile line fh and the imaginary slope line de intersect each other. It is in determining the position of this stake that my improved instrument is used.

In actual operation of the instrument the engineer first sets the slide bar 17 so that a given numeral on the scale 29 coincides with G on scale 26. The said given numeral on the scale 29 corresponds to the distance from the vertical center line aa of the finished grade to where the finished grade line G-b or Gz' intersects the finished slope line 6-0 or de. Let us suppose that the particular grade on which he is working has a width of 32 feet, the engineer then knows that the distance from the center line aa to the edge of the grade is'16 feet, or one-half of the width of the roadway, or if it is in excavation which in this case is being considered, the width is 22 feet to the point where the grade line produced intersects the slope line d-e. The scale 29 is then moved to a position where the point 22 coincides with G on scale 26. The engineer will set the slide bar 15 so that the numeral on scale 27 corresponding to the elevation of the finished grade at any particular station will coincide with G on scale 26 if he is using an elevation rod, or if he is using an ordinary leveling rod and is calculating his grade rod for each station, he will turn the slide bar 15 end for end in the frame and set the same so that the numeral on scale 28 corresponding'to the grade rod at the particular station will coincide with G on scale 26. The scales are then set for the particular section and station. We will assume that the engineer is using an elevation rod or arod reading elevationsdirect, and that he has his level set up and his rod adjusted to read the I proper elevation, and that the elevation of the finished grade at the particular station is 53. We will then assume that the rod man will place his rod at the point 32, say at a distance of 29 feet from the line aa. The engineer will then determine the elevation, which in this particular instance will be 59% feet. He then moves the frame 22 downwardly on the scale, due to the fact that the particular section is in excavation, until the line 25 rests over the point 29 on the red or excavation portion of the scale 29 as indicated by red characters. The line 25 will then fall on the point 57 on the scale 27 which is the elevation 01 the intersecting point on the given slope line de with a vertical line taken 29 feet from the vertical line aa. It will further be seen that the elevation of the lower end of the rod should correspond with the reading on the scale 27. Inasmuch as the rod elevation is higher than the said reading on the scale 27, the rod man then moves the rod out to a lower point on the surface f-h, say 30 feet from the line ara. The engineer again takes the elevation of the lower end of the rod, which is 58 feet. He then moves the frame 22 until the line 25 falls on the point on the scale 29 and then finds that the said line 25 falls on the point 58 on the scale 27 which agrees with the rod elevation; He then knows that this is the proper position for the stake, and that the said stake will intersect the slope line de. He then finds that the line 25 of the frame 22 falls on the point 5 on the lower part of the scale 26. This indicates the depth of the excavation at this sta-' tion below the stake.

Thus it will be seen that by the use of my improved instrument the stakes-may be set very rapidly and more accurately than heretofore where it is necessary to actually calculate the positions of each rod setting before it can be ascertained if the rod is in the proper position. L

If the stakes are being set for the cross section 7'lc it will be seen that a fill will be required at this point, and the black portion of the scale 29 may then be used instead of the red portion, and the frame 22 operated in the usual manner. In this connection it will be seen that the graduations on the scale 29 apply to both the embankment and excavation readings, so that when the said scale 29 is set for a given section, then the scale is adapted for comparison with the readings on the elevation scale 27, so that the said scale 29 does not have to be further adjusted either for embankment or excavationreadings, and

, whereby the depth of the excavation or embankment ma be immediately taken when the given rea ing of the scale 29 agrees with the given elevation reading of the scale 27, thus providin an instrument where an engineer mayvset t e stakes of a given section first adjusting the scale 29 and then the scale 27, after WhlCh all readings necessary for comparison for the setting of the stakes of that section may be obtained without further ad'ustment of the scales.

claim as my invention: 1..An engineers scale comprising a fixed grade scale graduated in opposite directions from a central zero point, an elevation scale slidably mounted adjacent to one side, of

said grade scale, a graduated horizontal scale adjacent to the opposite side of said grade scale, calibrated double in opposite directions from its ends to represent horizontal distances from the grade center to the points where the transverse profile line of a given section intersects the slope lines of the embankment and excavation of the grade of said given section, whereby by a single adjustment of said elevation scale for a given section,

I field elevation readings of said section may be compared with a given reading on either one of said horizontal scale calibrations, and

grade scale, a gra uated horizontal scale slidably mounted adjacent to the op osite side of said grade scale, calibrated dou le in opposite directions from its ends to represent horizontal embankment and excavation distances, whereby by a single adjustment of said elevation scale field elevation readings may be compared with a given reading on either one of said-horizontal scale calibrations, and when said readings check, the corresponding grade graduation will indicate she clorresponding embankment or excavation ept 3. An engineers scale comprising a fixed grade scale graduated in opposite directions from a central zero oint, an elevation scale slidably mounted ad acent to one side of said rade scales, a graduated horizontal scale adjacent to the opposite side of said grade scale, whereby b ,a single adjustment of said elevation sca e field elevation readings may be compared with a givenreading on said horizontal scaleon either side of the zero point, and when said readings check, the corresponding grade graduation will indicate the gorrtelsponding embankment or excavation es Moines, Iowa, Aug. 24, 1925.

\ OLE G. HERM. 

